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Caption

Silicon wafer production. Artwork showing the apparatus used to slice ultra-thin silicon wafers from an ingot (rod-shaped, blue). Silicon used in microchips needs to be precisely engineered for structure and purity. These wafers are machined from a large single-crystal ingot grown from high-grade polycrystalline silicon. The silicon is doped to produce a semiconductor with the required properties. Slicing is done with a diamond saw. Each wafer is 15-20 centimetres across and 250-600 micrometres thick. The insets (bottom) show close-ups of the slicing process. The wafers are then polished, oxidised and etched.